New NYPD cars getting new siren system

NEW YORK -- The New York Police Department plans to equip all of its new police vehicles with a siren system called the Rumbler.

The system emits woofer-driven sound waves that drivers and pedestrians can feel. The vibrations will be accompanied by a low whooping sound.

The NYPD's director of Fleet Service, Robert Martinez, told the Wall Street Journal that about 500 cars will be equipped with the new system by summer. Eventually, 5,000 NYPD vehicles will have Rumblers.

The agency buys about 1,300 new cars a year.

Police began using the system in a pilot program in 2009. Currently, about 150 cars have it.